Disc anchor

ABSTRACT

A disc type anchor for holding projectile emplaced marine mines. The disc anchor has a pair of flukes separated by an elongated slot which rotatably holds therein a torque arm. The flukes lie in a plane directed opposite to each other and on opposite sides of the plane of the rear area of the disc. The torque arm is bimodal and is restrained from forming an angle with the disc plane of more than 150* with either side of the disc. The bimodality of the disc anchor permits it to return to a flush digging alignment with a water bed whenever it has been upended.

United States Patent [191 Diorio July 3, 1973 DISC ANCHOR PrimaryExaminer-Duane A. Reger Assistant Examiner-Galen L. Barefoot 76 In tor:Frank Diori C scent D R.D. 4 ven 1 i gi 07849 A norney-Harry M.Saragovitz, Edward Kelly et a1.

[22] Filed: Dec. 30, 1971 [57] ABSTRACT [21] Appl. No.: 214,167

A disc type anchor for holding projectile emplaced marine mines. Thedisc anchor has a pair of flukes sepa- [52] US. Cl. 114/208 R, 1 14/206R rated by an elongated Slot which rotatably holds therein [5 1] Int. ClB63) 21/40 a torque arm. The nukes lie in a plane directed pp of Searchl Site to each other and on pp sides f the plane of the rear area of thedisc. The torque arm is bimodal and [56] References C'ted is restrainedfrom forming an angle with the disc plane UNITED STATES PATENTS of morethan 150 with either side of the disc. The bi- 2,894,474 7/1959Donaldson 114/208 R modality of the disc anchor permits it to return toa 2,948,249 8/1960 Gesner et al... 114/208 R flush digging alignmentwith a water bed whenever it 261,334 7/1882 Goldsmith ll4/206 R has beenu ended, 1,057,600 4/1913 Warner 114/206 R 11 Claims, 4 Drawing FiguresBACKGROUND OF THE INVENTION A need has long existed for an anchorsuitable for stabilizing air and artillery implanted marine mines. Infulfilling this need, the most significant design consideration hasalways been that of volume.

Existent practice in the prior art has been to utilize a type of foldinganchor modeled, in unfolded form, after a conventional small boatanchor. This folding feature permits the mine and anchor assembly to fitinto the required aerial dispenser. In general, provision was made tohave the anchor spring open into conventional form when the mineimpacted upon the water. Also, it should be noted, that the foldinganchor could never, because of its excessive size, be considered forencapsulation in an artillery projectile.

The prior art design required a number of stamped pieces, includingsprings, lever arms, shanks, flukes and different types of metal stocks.Fabrication of such a design necessitated use of a variety oftechniques, including riveting and brazing.

Despite the effort which has been put into development andsimplification of fabrication of the foldableanchor, it currently doesnot represent an acceptable solution to the problem of space limitation.An anchor capable of performing the same function as the foldableanchor, yet occupying a far lesser volume is required in order toimplement many of the more advanced concepts in water mining warfare.

SUMMARY OF THE INVENTION An object of the present invention is toprovide an anchor suitable for use with marine mines.

Another object is to provide an anchor suitable to packaging in seriallyand artillery delivered mine systerm.

A further objectis to provide an anchor realizing the above objectswhile occupying a volume of only about one-hundredth of that previouslyrequired.

Yet another object is to provide an improved shallow water anchor.

Still another object is to obtain an anchor achieving the above objectswhile requiring a reduced number of components in its construction.

The present improved anchor comprises an essentially flat platformhaving a forward area and a rear area, wherein the forward area,comprises two flukes having their respective pointed edges directedopposite to each other with respect to the plane of said platform, andfurther wherein said flukes are separated by an elongated passage; atorque arm rotatably attached at one end across that cross-sectionalwidth of said platform which comprises the elongated passage, saidtorque arm having a plane of rotation normal to said platform whereinsaid plane passes through, and symmetrically about, said passage; andrestraining means affixed across said elongated passage, saidrestraining means coacting with said torque arm to limit its rotation toabout 150 in a plane lying in that region of said passage locatedrearward of said restraining means.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a top perspective view ofthe present disc anchor.

FIG. 2 is a tilted front perspective view of the anchor.

FIG. 3 is a front plan view of said anchor.

FIG. 4 is a top perspective view of an alternate embodiment of thetorque arm of said anchor.

DETAILED DESCRIPTION OF THE INVENTION The present improved anchorcomprises an essentially flat symmetric platform 10 (see FIGS. 1, 2 and3). This platform is preferably circular in shape.

The platform is characterized by two flukes l2 and 14 which have theirrespective pointed edges oppositely directed. This feature imparts tothe anchor a bimodal digging capability, i.e., either side of the anchoris equally capable of digging into the bed of a body of water. Theflukes are separated by an elongated passage that forms a substantiallytriangular void 16 and a channel 18. This channel is (a) formed incommunication with an apex 19 (of about 60) of the triangular void 16,(b) aligned along a segment of the line intermediate the geometriccenter and the center of gravity of the platform 10, and (c) disposednormal to the base of the triangular void 16.

A torq'ue arm 20 is attached across that crosssectional width whichcomprises the apex 19. The torque arm may take a variety of forms. Theseinclude: (1) a cylinder having a U-shaped cavity 22 wherein the mouth ofthe cavity is directed toward the apex l9; and (2) a loop 23 (see FIG.4) that may be either circular, elliptical or square in shape. Thetorque arm 20 exhibits a plane of rotation which is normal to theplatform 10 and which passes about the channel 18. Also, said plane orrotation is symmetrically centered about the platform 10.

A restraining means 24 is affixed across the apex 19. The function ofthe restraining means is to limit the rotation of the torque arm 20 to asubstantially plane lying in the channel 18. The restraining means 24 isessential for preserving the bimodality or orientation insensitivity ofthe anchor. Bimodality requires that the anchor function identically inany position that it may find itself. Therefore, this requirementnecessitates,'in the present application, that the torque arm enable theplatform to readily flip from one side to the other and yet maintain aflush alignment with the water bed. This desired function is attainedthrough the use of the restraining means 24 which assures that thetorque arm 20 will not become stuck in a forward position. Rather, therestraining means 24 limits the forward rotation of the arm 20, thusobviating the possibility that the arm might become jammed forward.Hence, when the platform 10 is flipped; turned or twisted, it willreadily return to a flush digging" alignment with the water bed.

At the end of the torque arm 20 a connecting means (not illustrated)serves to tie a line 26 (see FIG. 2) to an anchored object, such as amarine mine.

The center of gravity of the anchor should be located slightly to therear of the geometric center at about point 28 (see FIGS. 1 and 4). Thislocation of the center of gravity may be effected thru the tapering ofthe width 30 of the platform 10, the taper running from the rear area tothe forward area.

The density of the material from which the platform 10 is made may varyconsiderably. However, its density must be greater than that of water(that is, it must have negative buoyancy). Platform density will bedictated by considerations of weight and volume which are themselvesdetermined by the holding power required of the anchor. The desiredholding power is computed by reference to a number of factors, namely,current velocity, river bed composition, and the drag coefficient of theanchored item. Drag coefficient is in turn related to the shape of theanchored item, its crosssectional area relative to the current flow, thedensity of the water, and the current velocity.

Tests have established that the present anchor can exert the sameholding power as a prior art anchor, while occupying only aboutone-hundredth the volume that said anchor would occupy in its foldedform. Also, the present anchor may be reduced in linear size to a degreenot attainable in the prior art. In addition, procedures of fabricationare greatly simplified, with a resultant reduction in cost. Accordingly,packaging of the disc anchor for purposes of aerial and artilleryemplacement of marine mines is greatly simplified. As a result, newconcepts in remotely placed water mines are now able to more fullyemerge.

It is thus seen from the above that the objects set forth in the Summaryof the Invention are among those made apparent from, and efficientlyattained by, the device of the preceding description.

I wish it to be understood that I do not desire to be limited to theexact detail of construction shown and described for obviousmodification will occur to persons skilled in the art.

Having described my invention, what I claim as new, useful andnonobvious and accordingly, by; this instrument, secure by LettersPatent of the United States is:

l. A disc type anchor comprising:

an essentially flat circularly shaped disc platform having a forwardarea and a rear area, wherein the forward area comprises two flukeshaving their respective pointed edges directed opposite to each otherwith respect to the plane of said platform, and further wherein saidflukes are separated by an elongated passage which includes;

a. a substantially triangular void having as its base a segment of theperiphery of said forward area and having its apex directed toward thegeometric center of said platform;

b. a channel formed in communication with said apex, lying along asegment of the line intermediate said geometric center and the center ofgravity of such platform, and disposed normal to the base of saidtriangular void;

5 a torque arm rotatably attached at one end across that cross-sectionalwidth of said platform which comprises the apex of said triangular void,said torque arm having a plane of rotation normal to said platformwherein said plane passes through,

and symmetrically about, said passage; and

restraining means affixed across said elongated passage, saidrestraining means coacting with said torque arm to limit its rotation toabout 150 in the 5 plane lying in that region of said passage located 1rearward of said restraining means.

2. The anchor as recited in claim 1 in which said anchor has negativebuoyancy.

3. The anchor as recited in claim 2 in which said torque arm includes aconnecting means located at free end of said torque arm, wherein saidconnecting means is used to tie the anchor to the anchored object.

4. The anchor as recited in claim 3 in which said torque arm comprises apartially split cylinder having the split portion thereof toward theapex of said triangular void.

5. The anchor as recited in claim 3 in which the apex of said triangularvoid forms an angle of approximately 60.

6. The anchor as recited in claim 3 in which the center of gravity ofsaid anchor is located on the line joining said apex and the center ofsaid disc, at a point to the rear of the center.

7. The anchor as recited in claim 6 in which the width of said disc istapered in a direction running from said rear area to said forward area,whereby the location of the center of gravity of said anchor can beestablished by a selective choice of the angle of the discs taper.

8. The anchor as recited in claim 3 in which said torque arm comprises aloop.

9. The anchor as recited in claim 8 in which said loop is circular inform.

10. The anchor as recited in. claim 8 in which said loop is ellipticalin form.

11. The anchor as recited in claim 8 in which said loop is square inform.

t t l i l

1. A disc type anchor comprising: an essentially flat circularly shapeddisc platform having a forward area and a rear area, wherein the forwardarea comprises two flukes having their respective pointed edges directedopposite to each other with respect to the plane of said platform, andfurther wherein said flukes are separated by an elongated passage whichincludes; a. a substantially triangular void having as its base asegment of the periphery of said forward area and having its apexdirected toward the geometric center of said platform; b. a channelformed in communication with said apex, lying along a segment of theline intermediate said geometric center and the center of gravity ofsuch platform, and disposed normal to the base of said triangular void;a torque arm rotatably attached at one end across that crosssectionalwidth of said platform which comprises the apex of said triangular void,said torque arm having a plane of rotation normal to said platformwherein said plane passes through, and symmetrically about, saidpassage; and restraining means affixed across said elongated passage,said restraining means coacting with said torque arm to limit itsrotation to about 150* in the plane lying in that region of said passagelocated rearward of said restraining means.
 2. The anchor as recited inclaim 1 in which said anchor has negative buoyancy.
 3. The anchor asrecited in claim 2 in which said torque arm includes a connecting meanslocated at free end of said torque arm, wherein said connecting means isused to tie the anchor to the anchored object.
 4. The anchor as recitedin claim 3 in which said torque arm comprises a partially split cylinderhaving the split portion thereof toward the apex of said triangularvoid.
 5. The anchor as recited in claim 3 in which the apex of saidtriangular void forms an angle of approximately 60*.
 6. The anchor asrecited in claim 3 in which the center of gravity of said anchor islocated on the line joining said apex and the center of said disc, at apoint to the rear of the center.
 7. The anchor as recited in claim 6 inwhich the width of said disc is tapered in a direction running from saidrear area to said forward area, whereby the location of the center ofgravity of said anchor can be established by a selective choice of theangle of the disc''s taper.
 8. The anchor as recited in claim 3 in whichsaid torque arm comprises a loop.
 9. The anchor as recited in claim 8 inwhich said loop is circular in form.
 10. The anchor as recited in claim8 in which said loop is elliptical In form.
 11. The anchor as recited inclaim 8 in which said loop is square in form.